1.A sample of size 16 is taken from a normal population. A sample mean of 15 is found.

(a) You know that the population standard deviation is 2. You wish to make a 99% z confidence interval for the true mean of the population. Use R to find z_/2 for this confidence interval. Paste your R output. Complete the 99% z confidence interval by hand. (3 marks)

You know that the sample standard deviation is 2.1. You wish to make a 99% t confidence interval for the true mean of the population. Use R to find t_/2,n-1 for this confidence interval. Paste your R output. Complete the 99% t confidence interval by hand. (3 marks)

I'm not sure how to put this into R commander. If you wouldn't mind helping me figure out how to solve these two use R that would be great thanks.